Harlequins got off to a flying start as Shaunagh Brown capitalised after an attacking mishap from Valkyries and Heather Cowell then touched down in the corner for their second.
Fiona Pocock finished off a well-executed set play for Quins’ third and she went over for her second and her side’s bonus point after 20 minutes.
Former Valkyries flier Cowell then got her second following a quick turnover and she grabbed her hat-trick when she finished off from a good Quins scrum.
Cowell went over ten minutes later following a strong set-piece as the visitors took a commanding 44-0 lead in at the break.
Davinia Catlin went over after the interval following a series of strong carries and Brown added her second score just a few minutes later.
Cowell went over for her fifth and then Natasha Bradshaw and Abbie Scott rounded off a clinical afternoon for Quins.
The youthful Valkyries did enjoy some positive passages of play but find themselves still chasing a first win of the season as they face a trip to Darlington Mowden Park Sharks this Saturday (kick-off 2pm).
Valkyries | 15 Vicky Laflin, 14 Carys Hall, 13 Lia Gingell, 12 Megan Varley, 11 Rebecca Herring, 10 Beth James, 9 Sian Moore; 1 Katie Phillips (Tremelling 45), 2 Lark Davies (C) (Johnson 75), 3 Lauren Leatherland (English 60), 4 Helena Bunce (James 55), 5 Ruth Black, 6 Maddie Roslund, 7 Charlie Wilcock, 8 Charlotte Browning
Replacements | 16 Carmen Tremelling, 17 Sophie Johnson, 18 Lizzie Binks, 19 Nat English, 20 Kirstin James, 21 Jo Richards, 22 Martha Setchfield
03m | Brown try 0-5
09m | Cowell try 0-10
14m | Pocock try 0-15
15m | Wooden con 0-17
20m | Pocock try 0-22
21m | Wooden con 0-24
24m | Bradshaw try 0-29
26m | Cowell try 0-34
29m | Cowell try 0-39
39m | Cowell try 0-44
43m | Catlin try 0-49
48m | Brown try 0-54
53m | Cowell try 0-59
60m | Bradshaw try 0-64
75m | Scott try 0-69
76m | Wooden con 0-71